Did some clean-ups and submitted a minimal patch set upstream.
I omitted the SparcStation-20 support for now, which made the patches for SparcStation-5 OBP cleaner, so there is a chance they will be accepted (my last patch was silently ignored for a month just because it was badly formatted, that's why I say "a chance", not "a good chance").
This means that if the patches will be accepted for the qemu 0.12, it will be possible to boot Solaris 2.5.1 and Solaris 2.6 kernels in the vanilla qemu with SS-5 OBP. I'll write a qemu/Solaris/sparc how-to.
No support for SS-20 (and SunOS 4.1.4 / Solaris 1.1.2) yet, as it is more buggy, and less requested. If someone thinks the support for SunOS 4.1.4 is important, feel free to write me. If you ever debugged a SunOS 4.x kernel (or have tools for doing it), please write me.